As a newbie Judoka, the hardest aspect of Judo for me are the throwing techniques, or Nage-waza. To improve in this area, I am thinking of working on 5 hand picked throws that are suitable for my body type until I become very proficient at performing them. The other throws I will learn during of course of regular training at some point.

Is this strategy a good idea?

I do want to learn as much grappling techniques, Katame-waza, and striking techiques, Atemi-waza, as possible. However, when it comes to throws, I just cannot see myself being able to perform all 67 throws with confidence in Randori anytime soon. Hopefully, with years of practice and hard work, this will be possible, but not in the foreseeable future.

That is a very good idea. I do however, recommend you give everything a try. In other words, if your instructor wants you to study something, you should try it.

Ultimately, with time, when you fight, you will notice that you have your "favorite teachniques". Most expert fighters have two or three throws that they do best.

I dont think anyone no matter how experienced, can do all 67 throws equal. So for your belt progression, you should try as much as possible, while keeping in mind that you will put effort into throws you are most comfortable with.

I just passed my blue belt test, and had to know throws that I never use, because they are not great for larger men. But I still studied them and showed that I understand that theory behind them. As I advance in Judo, I might even forget them, because I am focusing on throws that I am comfortable with (like uchi mata, o soto guri).

its a very good idea to study a few throws first, if I had to fight a guy that has don 10 throws a thousand times, I would be more careful than with a judoka that has don 1000 throws (I know that there arenít 1000 throws) ten times